Method for coupling a tool and tool holder using a tool assembly unit

ABSTRACT

The present invention provides a method for coupling a tool and a tool holder using a tool assembly unit including a measuring device which determines a position of the tool with respect to the tool holder, an alignment device adjacent to the measuring device which receives the tool holder, a moveable rod slideably disposed on the alignment device for engaging the tool and which moves the tool with respect to the tool holder to a desired position as measured by the measuring device. The tool may be affixed to the tool holder by heat shrinking.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of application Ser. No. 10/806,005,filed Mar. 22, 2004, which is a continuation of application Ser. No.10/047,674, filed Jan. 14, 2002, now U.S. Pat. No. 6,722,008, whichclaims the benefit of U.S. Provisional Patent Application Ser. No.60/315,630, filed Aug. 29, 2001.

FIELD OF THE INVENTION

The present invention relates generally to heat shrink tools and moreparticularly to a device for accurate assembly of a tool to a toolholder by the heat shrink method.

BACKGROUND OF THE INVENTION

Connecting a tool to a tool holder by the heat shrink method is awell-known process. An example of the general process is described inU.S. Pat. No. 5,311,654 issued to Harold D. Cook on May 17, 1994. Theheat shrink process is typically used with a tool holder having a borefor receipt of a tool having a shank. The tool holder is heated toexpand the tool holder bore. The shank of the tool is then inserted intothe bore. As the tool holder cools, the bore shrinks around the shankholding the shank within the tool holder.

The heat shrink method is an effective method for connecting a tool to atool holder. However, in most applications, the tool must be preciselymounted within the tool holder or the tool holder cannot be used. Itshould be appreciated that these tools are typically used in operationsthat require very precise alignment and positioning. Slight variationsin the alignment between tool and tool holder results in the productionof defective parts. One of the major disadvantages of known methods forconnecting a tool to a tool holder using the heat shrink method is theneed to measure each tool and tool holder and the inaccuracy that canresult from these repetitive measuring operations. Human error is asignificant factor. A worker must measure the tool length and the toolholder length and then adjust the position of the tool to get theappropriate overall length. To reduce human error somewhat, anothermethod employs a pre-qualified measuring rod to determine theappropriate depth of the tool within the tool holder. When this rodwears, the positioning is wrong and resultant tools and tool holderscannot be used. Furthermore, the heat shrink process must be donequickly to avoid down time when changing tools. If the heat shrinkmethod is slow, tool changes will be slow resulting in the overallslowing of the entire operation in which the tool and tool holder arebeing used.

Accordingly, it would be advantageous to provide a tool assembly unitfor rapidly and precisely connecting a tool to a tool holder.

SUMMARY OF THE INVENTION AND ADVANTAGES

It is an object of the present invention to provide a tool assembly unitfor coupling a tool and a tool holder. The unit includes a measuringdevice adapted to determine the position of the tool with respect to thetool holder, an alignment device coupled to the measuring device andbeing adapted to receive the tool holder, a moveable rod slideablydisposed on the alignment device and coupled to the tool, with the rodbeing adapted to move the tool with respect to the tool holder to adesired position as measured by the measuring device.

It is another object of the present invention to provide a tool assemblyunit for coupling a tool and a tool holder by heat shrinking. The unitincludes a measuring device adapted to determine the position of thetool with respect to the tool holder, an alignment device coupled to themeasuring device and being adapted to receive the tool holder, a heatingdevice slideably mounted on the alignment device and defining a bore forsliding a tool therethrough with the heating device adapted to beremovably mounted on the tool holder for heating the tool holder, amoveable rod slideably disposed on the alignment device and beingadapted to be coupled to the tool, with the rod being further adapted tomove the tool with respect to the tool holder to a desired position asmeasured by the measuring device.

It is still another object of the present invention to provide a methodfor coupling a tool with a tool holder using a tool assembly unitincluding a measuring device coupled to an alignment device and amoveable rod slideably disposed on the alignment device. The methodincludes the steps of mounting the tool holder on the alignment device,coupling the moveable rod to the tool, measuring an actual relativeposition between the tool and tool holder, moving the tool within thetool holder until the actual relative position of the tool relative tothe tool holder is equal to a desired position, and removing the toolholder and the tool from the alignment device.

It is still another object of the present invention to provide a methodfor coupling a tool with a tool holder by heat shrinking using a toolassembly unit including a measuring device coupled to an alignmentdevice having a heating device slideably mounted thereon and a moveablerod slideably disposed on the alignment device. The method includes thesteps of mounting the tool holder on the alignment device, heating thetool holder, coupling the moveable rod to the tool, measuring an actualrelative position between the tool and the tool holder, moving the toolwithin the tool holder until the actual position of the tool relative tothe tool holder is equal to a desired position, shrinking the toolholder around the tool, and removing the tool holder and the tool fromthe alignment device.

The subject invention provides many advantages over conventional toolassembly units by providing a tool assembly unit that rapidly andprecisely couples a tool and a tool holder. One of the major advantagesis reducing or eliminating the need to measure each tool and toolholder, thereby significantly reducing the inaccuracy that can resultfrom these repetitive measuring operations due to human error. Anotheradvantage is that rod wear does not result in improper positioning ofthe tool relative to the tool holder, thereby reducing cost by reducingthe number of resultant tool assembly units that cannot be used.Furthermore, the tool assembly unit of the present invention permits theheat shrink process to be done quickly to avoid down time when changingtools, thus reducing tool change time and encouraging an efficientassembly operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a perspective view of a tool assembly unit;

FIG. 2 is a perspective view of an alignment device used in the toolassembly unit of FIG. 1; and

FIG. 3 is an elevational view of the alignment device of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the Figures, wherein like numerals indicate like orcorresponding parts throughout the several views, a tool assembly unitis generally shown at 10. The tool assembly unit 10 includes a measuringdevice shown generally at 12, a heating device shown generally at 14,and an alignment device shown generally at 16. A controller 15 controlsthe various operations of the tool assembly unit 10. The controller 15includes a control panel 18 and a display screen 20. In the disclosedembodiment, a work table 22 is also shown for supporting the toolassembly unit 10.

The measuring device 12 is a standard tool measuring device such as, forexample, a microset unit sold by Tooling Systems Division ofFrankenmuth, Mich. The measuring device 12 includes an optical viewer 24mounted on a vertical tower 26. The optical viewer 24 in the disclosedembodiment is connected to the controller 15. In use, the desired lengthof the assembled tool and tool holder is inputted into the controller 15which automatically adjusts the optical viewer 24 to the correct heightalong the tower 26. In operation, once the tool 36 is correctlypositioned with respect to viewer 24, the correct height is known forthat particular desired tool and tool holder assembly.

In another embodiment, the optical viewer 24 is adapted for continuouslydetermining the position of the tool 36 with respect to the tool holder34. In addition, the controller 15 may be connected to the viewer 24 andthe tool 36 and tool holder 34 such that the optical viewer 24continuously detects the actual position of the tool 36 with respect tothe tool holder 34 and sends an electronic signal to the controller 15indicating the actual position. In response, the controller 15 comparesthe actual position with the desired position and moves the tool 36 withrespect to the tool holder 34 until the desired position is achieved.

The heating device 14 includes a heater 28 mounted on a slide tower 30.The position and operation of the heater 28 is controlled by thecontroller 15. Although two controllers 15 have been disclosed, it willbe appreciated by those of ordinary skill in the art that a singlecontroller or any other type of control unit could be used to performthe operation and positioning of the heater 28 and optical viewer 24.

With reference to FIG. 2, the alignment device 16 will be described. Thealignment device 16 includes a spindle 32 having an aperture 31 forholding the tool holder 34. In the preferred embodiment, the tool holder34 is held within the spindle 32 through a vacuum clamp. The tool to bemounted within the tool holder 34 is shown generally at 36. A push rod38 is adapted to reciprocate through the spindle 32 and tool holder 34to engage the shank 40 of the tool 36. The engagement of the rod 38 withthe shank 40 may be such that they are removably attached, coupled sothat the tool 36 rests on top of the rod 38 or any other suitable meansof coupling or mating such that the rod 38 may move the tool 36 withinthe tool holder 34 to the desired position.

The rod 38 is removably mounted to an adjustable mount 42. In thedisclosed embodiment, the rod 38 is mounted to the mount 42 through anadjustable screw 44. The rod 38 is removably mounted so that differentrod sizes can be used or the rod 38 can be replaced if it becomes worn.However, it should be appreciated that wear of the rod is not importantto the proper operation of the present invention since the rod itself isonly used as a push rod for positioning the tool 36 with respect to thetool holder 34 and the viewer 24. This operation will be described ingreater detail below.

The mount 42 is connected to an adjustment device comprising an airslide 46 and an adjustment shaft 48. In the preferred embodiment, theair slide 46 provides for rapid adjustment and the shaft 48 provides forfine adjustment. The fine adjustment in the disclosed embodiment isachieved through a gear box 50 and an electronic control 52. System airis controlled through electronic controls 54, which control pressurizedair through air lines 56. The electronic controls 52, 54 are coupled tothe controller 15.

A housing top surface is shown at 58 and a mounting bracket is shown at60. The top surface 58 and the mounting bracket 60 form the support forsupporting the alignment device 16 with respect to the heating device 14and measuring device 12.

With reference to FIG. 3, the operation of unit 10 will be described. Inoperation, the push rod 38 is initially moved to its lowest position. Inthis position, the push rod 38 can be replaced if necessary. Asdiscussed above, replacement of the push rod may be required if therehas been damage to the push rod or undue wear or if a different sizepush rod is required for a specific mounting operation. The controlpanel 18 for controlling the push rod 38 is illustrated schematically.The down button 61 would be engaged to move the push rod 38 down.

After the push rod 38 is down, the tool holder 34 is then placed in thespindle 32. The vacuum clamp is energized by pushing button 63 on thecontrol panel 18. This holds the tool holder 34 within the spindle 32.It is contemplated that a standard vacuum clamp would be employed or anyother suitable means of retaining the tool holder 34 within the spindle32.

At this point in the operation, if there is an existing tool 36 mountedwithin the tool holder 34, i.e., the intent is to replace the tool 36,the push rod 38 would be raised to touch the bottom of the cutting tool36. This would be controlled by a push rod up button 65. Then eithermanual measurement of the tool 36 and tool holder 34 would be done orthe measuring device 12 would be set at the predetermined dimension forthe tool 36 and tool holder 34.

The heating unit 14 would then be programmed through the controller 15which in this embodiment is being shown with the same numeric indicationas the push rod controller 15 and vacuum control. Again, as indicatedabove, these various controllers could be a single unit or various unitsto control the various operations of unit 10. The controller 15 wouldinitiate heating of the heater 28 and also move the heater 28 intoposition so that the bore 64 in the heater is positioned over the boreof the tool holder 34 to heat that region and expand it for receipt ofthe shank 40 of tool 36.

As illustrated in FIG. 3, the heater slide 30 is mounted through bracket62 to the spindle 32 of the alignment device 16. Once the tool holder 34is properly heated, the heating device 28 will move away from the toolholder 34 and either the existing tool 36 can be removed and a new toolinserted into the bore. Or if it is a first time assembly, a new tool isinserted. A fine adjustment knob 67 is then used to raise or lower thetool 36 to the crosshairs of the optical viewer 24. Once the tool 36 isproperly within the crosshairs of optical viewer 24, the properalignment between tool 36 and tool holder 34 has been achieved. Thevacuum clamp is then released by pushing vacuum clamp button 63 and thetool holder 36 and tool 34 are removed from the spindle 32 and placedinto a cooling rack for complete cooling.

The foregoing detailed description shows the preferred embodiments ofthe present invention are well suited to fulfill the objects of theinvention. It is recognized that those skilled in the art may makevarious modifications or additions to the preferred embodiments chosenherein to illustrate the present invention, without departing from thespirit of the present invention. Accordingly, it is to be understoodthat the subject matter sought to be afforded protection should bedeemed to extend to the subject matter defined in the appended claims,including all equivalents thereof.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology that has been used is intended to bein the nature of words of description rather than limitation. It will beapparent to those skilled in the art that many modifications andvariations of the present invention are possible in light of the aboveteachings. Therefore, it is to be understood that the invention may bepracticed otherwise than as specifically described within the scope ofthe amended claims.

1-23. (canceled)
 24. A method for coupling a tool and a tool holderusing a tool assembly unit comprising an alignment device, measuringdevice adjacent to the alignment device, and a heating device, saidmethod comprising the steps of: mounting the tool holder on thealignment device; heating the tool holder while the tool holder ismounted on the alignment device; establishing a desired position of thetool with respect to the tool holder; and moving the tool within thetool holder after heating the tool holder and while the tool holder ismounted on the alignment device until an actual position of the toolrelative to the tool holder is equal to the desired position.
 25. Amethod as set forth in claim 24 wherein the alignment device includes amoveable rod and the tool holder defines an aperture, said methodincluding the steps of slideably disposing the moveable rod in theaperture and engaging the tool with the moveable rod.
 26. A method asset forth in claim 25 including the step of moving the tool within theaperture until the actual position of the tool relative to the toolholder is equal to the desired position.
 27. A method as set forth inclaim 25 wherein the measurement device includes an optical viewerdisposed thereon for measuring the actual position of the tool relativeto the tool holder.
 28. A method as set forth in claim 27 wherein thetool assembly unit includes a controller coupled to the optical viewerand the alignment device, said method including the step of controllingthe moveable rod in response to feedback input by a user.
 29. A methodas set forth in claim 27 wherein the tool assembly unit includes acontroller coupled to the optical viewer and the alignment device, saidmethod including the step of controlling the moveable rod in response tofeedback from the optical viewer.
 30. A method as set forth in claim 24wherein the tool assembly unit includes a controller coupled to themeasuring device, the alignment device and the heating device forcontrolling each of the devices.
 31. A method as set forth in claim 24including the steps of cooling the tool holder to shrink the tool holderaround the tool and removing the cooled tool holder and the tool fromthe alignment device.